To avoid people thinking you’re stupid, above all you need to refrain from undertaking risky tasks for which you lack suitable knowledge or skills. That’s according to new research published in the journal Intelligence, which is the first to systematically investigate the kinds of behaviours that people consider to be stupid or foolish.

Balazs Aczel and his colleagues collected online news stories that contained descriptions of stupid behaviour, for example from the New York Times, the BBC and the gossip site TMZ. They also asked 26 university students to keep a diary for five days of incidents they experienced that involved people acting stupidly. In the end, the researchers ended up with 180 stories, a small number of which they deliberately manipulated to alter the consequences of the stupid actions and the responsibility level of the perpetrator.

The stories were condensed down to brief (roughly two-sentence long) descriptions of the events, and shown to 154 undergrads in Hungary. The students rated the intensity of the stupidity on display and also rated how much 30 potential psychological factors (including things like overconfidence and fatigue) were to blame for the stupidity.

After analysing the students’ scores and explanations for the stories, the researchers deduced that there are three main categories of what people consider to be stupidity:

“Confident ignorance” which is when people engage in risky actions for which they lack the prerequisite skills or knowledge. Such actions received the highest ratings of stupidity and were encapsulated by a story of burglars who thought they were stealing mobile phones, but actually stole GPS tracking devices which allowed the police to find them.

“Lack of control”, resulting from obsessive, or addictive behaviour. For example, a person who cancelled a meet up with a good friend because they couldn’t pull themselves away from a video game. This category was intermediary in the hierarchy of stupidity.

“Absentmindedness – Lack of practicality” which refers to instances when people fail a practical task, either out of distraction or because of a lack of practical skills. This category was encapsulated by someone inflating car tires too far. In terms of stupidity ratings, the participants were most lenient toward these kind of acts.

Unsurprisingly, in each case, the participants rated acts as more stupid when the consequences were more serious, and when the perpetrator was in a position of more responsibility. This last point “suggests an explanation as to why experts and people in leadership positions receive more fervent scorn,” the researchers said.

Aczel and his team speculate that people are generally rather preoccupied by acts of stupidity, either committed by themselves or others, because to maintain this vigilance is beneficial. By striving to avoid the label of stupidity, we are all galvanised toward avoiding actions, such as overconfidence, or mindlessness, that are likely to lead to misfortune or loss of status.

This research has some obvious limitations – most glaringly that it relies on the judgments of a group of students in Hungary. It remains to be seen whether the results will generalise. Nonetheless, with so much published research and debate on what counts as intelligent behaviour, this study offers a refreshing change of direction. As the researchers put it, “the study of intelligent behaviour may benefit from understanding its flipside, unintelligent behaviour, which in turn may be inherently linked to our conception of stupid actions.”